function onChange_Vehicle() {
	var vehicles = document.getElementById('vehicles');
	var marks = document.getElementById('marks');

	// delete marks
	while ( marks.firstChild != null ) {
		marks.removeChild(marks.firstChild);
	}

	// add new marks
	var option = new Option('выберите марку', '0');
	marks.options[0] = option;
	if ( vehicles.value ) {

		// search for current vehicle
		for ( var i=0; i<vehiclesMarksModels.length; i++ ) {

			if ( vehiclesMarksModels[i].id == vehicles.value ) {
			// if found...

				// put marks for current vehicle in marks select
				var marksInfo = vehiclesMarksModels[i].marks;
				for ( var j=0; j<marksInfo.length; j++ ) {
					option = new Option( marksInfo[j].name, marksInfo[j].id );
					marks.options[j+1] = option;
				}
				break;
			}
		}
	}
}

function onChange_Mark() {
	var vehicles = document.getElementById('vehicles');
	var marks = document.getElementById('marks');
	var models = document.getElementById('models');

	// delete models
	while ( models.firstChild != null ) {
		models.removeChild( models.firstChild );
	}

	// add new items
	var option = new Option('выберите модель', '0');
	models.options[0] = option;
	if ( marks.value ) {

		// search for current vehicle
		for ( var i=0; i<vehiclesMarksModels.length; i++ ) {

			if ( vehiclesMarksModels[i].id == vehicles.value ) {
			// if found...

				// search for current mark
				var marksInfo = vehiclesMarksModels[i].marks;
				for ( var j=0; j<marksInfo.length; j++ ) {

					if (marksInfo[j].id == marks.value) {
					// if found...

						// put models of current mark in models select
						var modelsInfo = marksInfo[j].models;
						for ( var k=0; k<modelsInfo.length; k++ ) {
							option = new Option(modelsInfo[k].name, modelsInfo[k].id);
							models.options[k+1] = option;
						}
						break;
					}
				}
			}
		}
	}
}